Electronic device



July 22. 1952 o. G. wlLLlAMs 2,6043588 ELECTRONIC DEVICE'.

Filed Nov. 9, 1948 l I l l l I l I I (a) fl H (c) L n (d) 9 o 2 3 4 s s 7 8 9 o 2 L l |(z) n n (b) w [L (C) A 7" TOR/V17),

Patented July 22, 1952 UNITED sTATEs PATENT oFFIcE' ELECTRONIC DEVICE- Owen Grilfith Williams, London, England, as-

signor =to International Standard Electric Corporatiom New 1 York, N.

Delaware Y., a corporation of Application November 9, 1948, Serial No. 59,103

In Great Britain NovemberlL 1947 This invention relates to electronic pulse .sys-

i tems and in particular to systems Wherein apulse of electrical energy Per'time period, which consists in measuring a secondseries of time periods im'tia'lly in synchronism With and normally the same lengthv as those of the first series, in producing'an output pulse at an invariable position 'in each of the said second series of time periods,

and in either lengthening or shortening any one of 'the said'periods in the secondseries whereby the second series-of'time periods become staggered, relative to the first series andin consetluence the position of the output pulse relativeto the saidl first series ,of time periodsis thereafterchanged.

A second feature of the inyention is'a lmethod of'changing'the position in a first series ofrecurri'ng invariable time periods of an output pulse of electrical energy per time period, which conssts in measuring a second series of time periods Vinitially vin synchronism with .and normally the same length as those of thel first series; in producing :anV output pulse at -an invariable position ineach of the said second series of timeperiods, and in either lengthening or shorteninga number of consecutive` or nonconsecutiveperiods in said second series wherebythe said second series of time periods becomes staggered relatiyeto the first seriesand in consequence the positions of 'the output pulse relative to said first periods are successively changed.

third feature is a method for the step-bystep-alteration of the position in a first series of recurring invariable time'periods of an output pulse of electrical energy per'tinfie periodx which consists in measuring a second series of time periods initially in synchronism with' and nor'- v mally the same length as those of the first series, in-producing an output pulse at an invariable po- Vsition in-each-of the said second series of time periods and in either lengthening orshortening a plurality of said measured time periods by equal amounts lwhereby a step-by-step change in the 11 Claiins. (Cl. 250-27) position of the output pulse relative to theinvariable time periods is 'eifected A further'feature of the invention` is a device vfor changing the position of anoutput pulse'of electrical energy occurring in each of' a series of recurring invariable time periods comprising means formeasuring such time periods, means for generating an output pulse at aninvariable position in eachv of said' measured time Vperiods and means for staggering said measured'timeperiods relative to the invariable time periods whereby the positions of the output pulses relative to the said invariable time periods arethereafter changed. o

Another feature is a device for the step-bystep selection of any one of a number of predetermined positions in at leastv one of a recurring series of invariable time periods, for the transmission of a pulse of electrical energy, 'the'periods being defined by a train of pulses of electrical energy, having a predetermined number of pulses ineach of saidinvariable periods, comprising means for measuring such time periods, start means for said measuring means 'adapted'to beactuated,l during operation by the firstpulses of anyv one of the/said measured time periods, means for transmitting an output pulse onceata particular ,instant during each measured time period andmeans for either lengthening orlshortening anyone o f said measured time pericds. by selection steps each equal in length toat'1east one-interval between successive pulses of thesaid train of pulses, whereby the output pulseslare thereafter transmitted at absolute time positions -displaced from those at which they would otherwise be transmitted by'a step equal to said one or f' more pulse intervals.

.The embodiment of the invention which will be described is a gas tube line selector for` an-automaticVtelecommunication system. This selector may 'employ only one tube. It will be shown how that in response, eg. to pulses controlled by dialling, the timingpulse corresponding to the vparticular line required'may be chosen from a number of possible timing pulses and' applied to the outlet. 'It Will be understood that there "is a time pulse at a particular timeV position representative of each line. The line selected' may correspond exactly .with the number' dalledfor may, be-the 'complement of it." `which of these possibilities occurs depends on the internal construction' of the tubes, both types will be described.

The nature of the invention willjbe more clearly understood by reference to theA following de- 3 scription and to the accompanying drawings in which:

Fig. 1 shows a gas tube line selector having ten lines selectable in which the line complementary to the number of impulses received will be chosen.

Fig. 2 shows a gas tube ten line selector in which the line corresponding to the number of impulses received will be chosen.

Figs. 3 and 4 give the waveforms to be found at certain points of the tube circuits, the former being related to Fig. 1 and the latter to Fig. 2.

In Fig. 1 we have shown a ten cathode gas tube having a main anode A, nine cathode points B which are commoned up externally and an individual cathode C from which the output is taken.

A secondary gap G is placed adjacent to the first cathode BI, the auxiliary anode D for this gap being fed separately from the main anode A.

Consider the case when the first timing pulse of a cycle of ten such pulses is applied to A from lead LTP via a condenser J. It is arranged in a manner later to be described in detail that this strikes the first gaps, then succeeding gaps are broken down in turn by following pulses and the Vtenth pulse will appear on the last cathode C.

vthe secondary gap being suflcient to allow the i firstftwo gaps to break down by the application of onelpulse to the anode A. The ninth timing pulse in a cycle then appears at C instead of the tenth. i

Shouldthe secondary gap only remain discharged for a fixed period of time it will thus be evident vthat the last cathode Would continue to select line.9 and'not slip along the line 8, providing.A this period of dischargeis no longer than the time interval between therepetition of like position timing pulses, i. e. 100 ;i secs. in the case of 10 kc./s carrier frequency for the line pulses.

Such a longpulse of 100 ;i secs. for application lover Vlead X to anode D could originate from a telephone dial, one .pulse for every unit dialled.

.Thedialling Vof 4 will then cause the application VVof a continuous pulse 400 p. secs. long to the secondary'gap B and thus phase advance the selector. by 4 timing pulses so that the pulse corresponding to line 6 will continue thereafter to appear at the last cathode O. In this case eitherthe complementary number to the line required has to be dialled, or some satisfactory correction' must be included in the circuit.

Thewaveforms at the output cathode C are Villustrated in Fig. 3 (b),` (c), and (d), that of -the cy'cles of' timing pulses forming the subject vof Fig. 3(a); V3(b) shows the normal operation vofthe tubeand (c) and (d) theoutput during `and after the application of a single 100 ;t s.

pulse. '-During the receipt of thedialling pulse ,it is clear that the tube becomes a nine point tube-.(as in after which (in (11)) Vit reverts to itsnormalcondition.

AAnother form of the embodiment of the invention gives adirect result from the dialled number i. e. .anysuch complication as complementary dialling is unnecessary.

`In thisjcase a ten line system will require eleven cathode points and one secondary gap in the tube which may have internally commoned cathodes as shown in Pig. 2. During normal operation in this case it is arranged that the secondary gap G is discharging so that there is electrically a ten point tube, .the first two anodecathode gaps being broken down by one pulse applied to the anode; the wave form of the output taken off C is shown at Fig. 'i (b) the timing pulses being represented at 4 (a). Now for each unit dialled a negative square wave is applied fromX to the auxiliary anode D of sufficient amplitude to extinguish the discharge already occurring there and of sufficient duration to keep it extinguished for one whole cycle of the operation of the tube. The tube becomes an eleven point tube and the pulse selected by the last cathode C is delayed by one timing pulse. This is illustrated at Fig. 4 (c). Reversion to the normal operating conditions is indicated at Fig. 4 (d).

The sa'me conditions apply to this form of the embodiment as to the rst one, i. e. the long pulse, a ;i secs. square wave (negative in this case) or the combined long pulse resulting from the dialling of a digit greater than one is obtained from the dialling apparatus and applied to thesecondary anode D.

Tubes such as have been considered may be provided with any one of several priming methods for ensuring that the commencement of discharge will always take place across the same gap. In Figs. 1 and 2 at P there is shown a separate priming gap which is maintained in a continually discharging state so that at the end of each succeeding cycle of the tube and after the local extinguishing device has operated the raising of the level of ionization is initiated in the vicinity of this priming gap. The nearest gap to the priming gap will therefore always be the first to strike and this has been referred to above as thefirst gap. Such an arrangement is disclosed and claimed in the application of A. H.

Reeves, Ser. No. 19,084, filed April 5, 1948, Patent No. 2,520,171.

One alternative starting arrangement is vto have one gap with a lower striking potential than that of any of the others. This is conveniently arranged by making that gap of shorter gap length., In the tube shown in VFig. 1 and described above, the nearest anode/cathode gap to the secondary gap, that shown at S, could be made shorter than the remainder of similar gaps and the priming gap P need not then be fitted. Discharge initiated by timing pulses Would always then commence from this gap, their amplitudes being sufficient to break down Vthis shorter gap but insufficient to strike any gaps of the normal length in the absence of other ionisation in the tube. Such arrangements as this are described and claimed in the application of A. H. Reeves, S'er. No. 763,655, filed July 25, 1947.

It Will -be apparent to those skilled in the art that the basis of the embodiment described lies in the arrangement whereby the first timing pulse after4 the end of atime period does not always have the same effect when applied to the tube. In the two forms of the embodiment so far described above it will be observed that under certaincircumstances already detailed, the level of ionization in the'tube. is raised so that such a pulse causes twoneighboring gaps to break down. At a lower level of ionization the pulse only causes discharge across one of the gaps. Another posz? iii associationfwithf affdelay.: circuitiicanifulfill fall :the'aopterating requirements :of :a I step-by -step v'selectingfidevice; :iThe nel'ay '.circuitzawhich ;might straight-forward idelay'.: line; is '.femployed'during ziloperati'onto::absorb timing :pulses :which| hitherto have'fbeenusedfto': Striker-father i'discharge'. gaps i vof -the fir'sttube.- T:If,".:for:example;= the fsecondaryfgap i timing'pulse :isrenabled to fc'ausemhe ``disch'arge'-1to :.'ispread'ztoz'ibothfofthe i"d'ina1-y:.gaps-.-and fth'eV re- `-n'ra'iriing; inne pulseszzintthe *.timei'iperio'dsiare ab- -1 sorloed` :int f. 'e' de'lay Circuit. .'Thefi output 'limay vfei'th'er :beata-'Ken fromzthetfdelay .circuit .orffromi the :second :of 'the *two ordinary.V gaps, si. thetgap further from the secondary gap. On receipt ofa fc'negative, dia1-'controlled, long- |pulse :fat :the fsecizondary'anodefllinfthe usual way thez-normalfsecondarytgapdi'scharge? is fextinguished. "Two- .tim- I .king ipulsesare nowi-frequired'-tostrikeifthe' two ordinary :;gaps, nine''` 'are f-a'bsorbed in i'the': delay circuits as before and it will be understoo'dthat the' output. has-stepped'forward one timing pulse.

According to the application Ser. No. 19,084 a' sequence discharge tubeis provided with a primving vgap placed in geometrical relationshipwith one vormore'gaps of an ordered, array vofjdischarge gaps whereby the ionization level at'` the same gap or gaps ofthe'arrayzmaybe'regulatedgby the discharge current passed by the said prirning gap.

'I'hisjpossibility enables a tube havingeonlythree ;jfischargegapsnamelyea prinil ng gap ,`i:andftw 'ordinary janode/cathode vgaps; infassociation;with

`'a-delayffcircuit;'to carry'outfi't'h'e' functionsrof al... step-by-step selection device.

A possible method of operation of such a device is now to be described. The priming gap is' maintained normally discharging but not at a high level of ionization. The first two timing pulses after the end of a time period strike in turn the ordinary gap .nearer the priming gap and the other ordinary gap. The remaining eight pulses in the time periodare absorbed in the delay circuit and the output is taken either from the delay circuit or from the second ordinary gap. A dialcontrolled long pulse, positive in this case, is applied to the priming gap and hence the level of ionization is raised. On the next receipt of a first timing pulse' the result Will be the striking of both ordinary gaps consequent upon the regulation of the ionization level of those gaps by the priming gap discharge. The delay circuit absorbs eight timing pulses as before and it will -be seen that the output has stepped backwards one timing pulse. The effect is comparable With that obtained with the type of tube shown in Fig. 1.

Having shown that four and three gap tubes may be employed for step-by-step selection devces, as well as the multigap sequence discharge tubes, it Will now be demonstrated that Satisfactory arrangements may be made for two gap tubes similarly to be employed. Such a tube requires a common anode and two cathodes onev anode/cathode gap -being shorter than the other.

iS-:alsoarequiredl .thatfathe:timingxpulses :shallsbe .sufiicient :amplitude .=themselvesiitoffstrikeflfthe shorter: :gap whenilittlecor nov '.ioniza'tionE remains A'in "the ;tube andlto ;strikeL-thef 'longer '.gap fwhenthe :.Asf in ltherca'se of fthe'foursandithreet:gap' tubes --s`o'f.;with .the two. '.gapltubei'ar.delayfcircuit'iis lem- ..-p1oyed. possible' 'method'ffiof operation is.: for

4the shorter gap to be normally maintainedfdis- .'charging. Thelfirstitiming .'pulsesfafter the'` end of Sa :ti-me :period isuipplied ito .the zl'o'ngerx-gapf 'to break'fiit fdown and ther'emaining -lnine pulses Vare ;.absorbedin the delay'circuit.` 'JAgainithejioutput :can beztaken'lfrom1the=ldelayi circi'iit'orl ."fromzithe -c'athfodev belonging :'tol .thelonge'rf gap'; "i

'lDi'allingmow zis arranged.'.towresultfi thelffex- '1tinguis'hing -..o`f Y'the ?discharge fila'cross* thelfshorter ffgap'lb'y th'eapplicationfthereto of a'v negative''long ."pu'lse`, s'o'thatitheinextfirsttiming pulseofafcycle :st 'ikes this shOrterzgap: 'TThe'secondtiming pulse f `'willi.thene'auz-:eLtlfielonger 'gap `to f strike; =as` before `'fnine VAp'i'il'ses i are fabso'i'be'd* in' the delay 1Circuit :and

wthe output :williv have-stepped' along. one 1 timing pulse response 'to'fithe receipt -o'ff 'one fdi'al'c'onf-'lgten' 'tiniing pulses, 'correspondifng 'tof' the applica- `-`'tion'-Cf-1-theinvention to "'a'isfas tube ''-linel Vselector fi'havingften' outlets, there 'is no reasorfj-why `Jthe number'of Jtiming-puls'es should not '-be V( lifierent nor, of course is the invention limitedfto-th'effre- -;quenciesl quoted' or-to-'-any-part icular fifrequencies. '-Vl/'hiile`l the prin'eiplesf of the linvention have been escribed-above' in' connection with'lspecificem- `v'bo'diinents an'd 'f'particu'lar' 'modifications `'-thereof, 'fit' is to' she-.ciearlyu-nders'to'od thatlthis description {'is'= made only i'by wa'y of =`e'xamiple fan'dz not-'as a e'f positionof i an feaehfof'a' seriesf-'f Vrecurringriods comprising means for n'feas f Flperiods, means conti'lle'd 1 said f ==measuring means for generating an output pulse at an invariable position in each of said measured time periods and means for temporarily altering the operation of said measuring means so as to shift the position of one output pulse relative to its invariable time period, Whereby the positions of the output pulses relative to the said invariable time periods are thereafter correspondinglv shifted.

2. A device for changing the position of an output pulse of electrical energy occurring in each of a series of recurring invariable time periods as claimed in claim 1, wherein said means for temporarily altering the operation of the measuring means shifts the position of the output pulse so as to make it occur earlier in its invariable time period.

3. A device for changing the position of an output pulse of electrical energy occurring in each of a series of recurring invariable time periods as claimed in claim 2, in which the means for temporarily altering the operation of the measuring means may be operated for sucoessive time periods whereby the resulting output pulse is shifted by a time period equal to the sum of the individual shiftings of the pulse time periods which have taken place.

4. A device for changing the position of an output pulse of electrical energy occurring in each of a series of recurring invariable time periods, as claimed in claim 1,' in'which the said invariable time periods arez defined by a train of pulses of electricalV energy having a predetermined number of pulsesV in each of said invariable time periods and in which the change of any one of the said measured time periods is a multiple of the inter-pulse time periods between consecutive or vnon-consecutive pulses of the said train of pulses. v

f 5. .A device for theV step-by-step 'selection' of any one of a number of predetermined positions in at least one of a' recurring series of invariable vtimeperiods, for the transmission of a pulse of electrical energy, the period being defined by a train of pulses of electrical energy having a'predeterminednumber of pulses in each of said'in- -variable timeperiods,v comprising means for measuring such time periods, start means for'said measuring means adapted to be actuated, during operation, by the first pulse ofgany one of the said invariabletime periods; means controlled by said measuring means for transmitting an output pulse once at a particular instant during each measv.';ured time period, and means for changing'any one of said measured time periods by selectingl steps .each equal in length to at least one interval between successive'pulses of the said train of pulses, whereby the output pulses are thereafter transmitted at absolute time positions displaced from' those at which they would otherwise be transmitted by a step equal to a multiple of said pulsev intervals.

6. VA device, as claimed-in claim 1, in which the said means for altering the operation of the measuring means is responsive to a pulse which isV additional to the train of pulses and which consists of one "long pulse, ,or a plurality of immediately successive f'long pulses, each long pulse being of the same duration as the said invariable time period so that at whatever time position in a measured time period a "long" pulse is arranged to be effective it will be effective either. in the measured time .period during which it starts or in that next following.

.7. A device, as claimed in .claim 1, in which ;is'normally maintained in a discharging condition, aparticular'one of said gaps being designed to initiate a discharge upon the receipt at the de- ;vice of the said "long pulse to effect the shortening of either the measured time periods during Number thesaid means for measuring such time'periods 'is composed in partof a cold cathode gas discharge -tubehaving at least two discharge gaps. 8. A device, as claimed in claim'l, in which the said means for measuring such Vtimeperiods comprises a delay oircuit in addition to the cold'cathode discharge tube having .two or more discharge gaps.

9. .A device, as claimed in claim 8, in which means isv provided for normally maintaining a particular one of said discharge gaps lin a discharging condition and to extinguish it on the receipt at the device of a "long" pulse so as to elfectthe lengthening of either the 'measured time period during which the additional pulse is received or that next following.

. 10. A device, as claimed in claim 1, in which the said means. for'measuring such time periods comprises a cold cathode gas discharge tube having at least two discharge gaps none of which which the additional pulse starts or those next following.

11. A device as claimed' in claim` 10 in which the particular one gap is immediately adjacent to that across which the pulseof the said train of pulses received first during any one of said measuredl time periods causes a discharge to occur..l

OWEN GRIFBTTH WILLIAMS.

` RFERENCES CITED The Vfollowing references are of ,record in the file of this patent:

UNITED STATES PATENTS Name Date 2,291,040 Holden July 28, 1942 2,422,698 Miller l June 24, 1947 -2,432,292 Deal Dec. 9. 1947 

